package com.ruirui;

public class TestString {

    public static void main(String[] args) {
        String s = "hello world";
        StringBuilder sb = new StringBuilder(s);
        sb.append("hello java");
        System.out.println(sb);
        System.out.println(sb.reverse());
        sb.getChars(0, 5, new char[5], 0);
    }
}
